Die for deforming material in a joining tool, joining tool and method for identifying and/or decetcting the condition of a die

ABSTRACT

A die for deforming a workpiece material in a joining tool comprises a head with a top side partially defining a cavity in which the workpiece material is to be deformed, a bottom side opposite the top side, a lateral side arranged between the top side and the bottom side, and a stem which extends along a longitudinal axis from the bottom side of the head. The die further comprises an identification tag, preferably an RFID tag, having an antenna for receiving and/or transmitting a signal, and a storing element for storing information, and the antenna is wrapped circumferentially around the head, such that the antenna entirely surrounds the head. The head may also include a groove extending around the head on the lateral side with the antenna arranged in the groove. Additionally, the die may include a recess with the storing element located in the recess.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from European Patent Application No.17157251.4, filed on Feb. 21, 2017, the disclosure of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a die for deforming material in ajoining tool having a head comprising a top side defining a die cavityin which material is to be deformed, a bottom side opposite the top sideand a lateral side arranged between the top side and the bottom side.The die further comprises a stem which extends along a longitudinaldirection from the bottom side of the head.

In addition, the present application relates to a joining tool systemcomprising a die, a die holder in which the die is supported such thatthe die is operational with the die cavity being exposed to receivematerial and a setting tool supported by one arm over the top side ofthe die.

Finally, the present invention relates to a method for identifyingand/or detecting the condition of a die, such as, among other things,damage of the die or a complete absence of a die from the die holder.

More particularly, but not exclusively, the invention relates to dieused in fastening application. The die can be used in particular forself-piercing riveting, punch riveting or clinching.

Fastening arrangements with a die like self-piercing rivet arrangementare used in particular, but not exclusively, in the automobile industryto produce vehicles bodies.

Self-piercing riveting or punch riveting has recently become establishedas a production method, since it is suitable in particular forconnecting different materials. In self-piercing riveting a rivet of aparticular configuration is inserted into a workpiece such as, forexample, one of more sheets of material, without full penetration suchthat a deformed end of the rivet remains encapsulated by an upsetannulus of the material. The rivet typically comprises a head and apartially hollow cylindrical shank that terminates in an annularpiercing edge. The rivet is driven into the workpiece arrangement by apunch of a setting tool. The die acts on the underside of the workpiecearrangement. A shank of the rivet pierces the top sheet and then flaresoutwardly in the die such that the sheet material forms an annulus in adie cavity that encapsulates the shank.

In addition to the punch and self-piercing riveting method, clinching isalso used. Clinching can be carry out with or without an auxiliaryjoining element. The assembly is carried out using a die and a punch toplastically form an interlock between the partners (for example two ormore sheets of material). The die ensures that material flows radiallyoutwards, such that an undercut is formed.

The forces which are to be applied to the workpiece during the joiningmethods described above will be high in many applications and the die istherefore subject to very high loading and wear. Dies can crack and/orbreak into pieces. Thus, the die needs periodic inspection andreplacement, in order to ensure that the needed strength of the joint isachieved.

The life expectancy of a die is dependent on many factors including, forexample, the number of cycles to which it is subjected, the settingforces, the materials of the workpiece being used, the alignment of thedie to the workpiece and the punch, the material properties of the die(the life expectancy can be reduced particularly when use is made ofcomparatively hard materials or materials having a low ductility), thequality of the surface on which the die is supported, the degree ofretention of a die holder and instances of operation (erroneous or fortesting purposes) in which the setting tool impacts directly on the die.

A faulty die can cause unsightly distortion of the sheet material andthe strength of the joint may be compromised as a consequence.

There is therefore a need to check for faults in a die.

It is known to use a fluid medium to check for faults in a die.DE102004002593 discloses a method using a fluid medium supplied tocavities in regions of a joining tool system via channels. The pressureor flow rate of this medium is measured. The actual value of thepressure or flow rate is compared with an intended value and the resultof the comparison is the basis of the checking process. Not only doesthis method require an expensive investment in machinery but it alsointroduces delays into the rivet cycle time.

Document DE102012207391 discloses a device with a rivet unit having apunch and a die. The device further comprises a test element with asensor to determine eventual damages in the die. The sensor is movedafter each riveting operation toward the die to check for any damages.The sensor is an ultrasound sensor, an image sensor, an inductive sensoror a thermal sensor and is driven around the die. This method introducesdelays into the rivet cycle time. The manufacturer has to balance thequality control benefits provided by performing the checking process atregular intervals against the time it takes. If the checking processreveals a broken or missing die then all the joints performed since thepreceding check are potentially faulty and they either have to bechecked or scrapped.

SUMMARY OF THE INVENTION

It is one object of the present invention, amongst others, to obviate ormitigate at least one of the aforementioned disadvantages and to providefor an improved or alternative die which allows an easy determination ofits eventual damages. It is also an object of the invention to provide ajoining tool system and a method for identifying and/or detecting thecondition of a die that enables a direct identification and detection ofthe condition of a die without expensive investment in machinery andwithout introducing delays into the joining cycle time. In the presentapplication, the term “condition of the die” is intended to include,amongst other things, damage of the die, the complete absence of a diefrom a die holder, the service life of the die or the technicalcharacteristics of the die.

To this aim, according to the invention, it is provided a die fordeforming material in a joining tool having:

-   -   a head comprising a top side defining a die cavity in which        material is to be deformed, a bottom side opposite the top side        and a lateral side arranged between the top side and the bottom        side, and    -   a stem which extends along a longitudinal direction from the        bottom side of the head,

characterized in that

the die comprises an identification tag having an antenna for receivingand/or transmitting signal and a storing element for storinginformation, and in that the antenna is wrapped around the head, suchthat the antenna entirely surrounds the head.

The present die allows a quick and easy identification through theidentification tag. The position of the antenna for receiving and/ortransmitting signal is such that any damages that occur in the die willalso damage the antenna, enabling the antenna to receive or transmitinformation. The antenna can thus act as a sensor. The position of thestoring element and antenna does not structurally or functionally affectthe die. The present die is easy to manufacture, without any expensiveinvestment in machinery. Besides, the position of the antenna (entirelyaround the head) could allow a 360 degrees reading capacity. A readerdevice can communicate with the antenna independently from theorientation or arrangement of the die.

According to an aspect, the die comprises a groove extending around thehead on the lateral side between the top side and the bottom side andthe antenna is arranged in the groove. The antenna does not protrudefrom the head of the die, which reduces the risks to deteriorate theantenna during the manipulation of the die.

According to an aspect, the die further comprises a recess and thestoring element is arranged in the recess. The storing element does notprotrude from the die, which reduces the risks to deteriorate thestoring element during the manipulation of the die. The recess may belocated at any place, and not necessarily close to the antenna. Thepositioning also reduce the contamination of the identification tag.

The identification tag is thus integrated to the die and its positioningavoid any premature or irregular wear.

According an aspect, the recess is provided on the lateral side of thehead. The recess is thus easy to manufacture without modifying thegeneral shape of the die or the functional surfaces of the die.

According to an aspect, the distance between the antenna and the topside is smaller than the distance between the storing element and thetop side. More particularly the antenna is arranged in the vicinity (andas close as possible) of the top side such that a deterioration of thetop side of the die will lead to a deterioration of the antenna. If theantenna is provided in a groove and the storing element is provided in arecess, the grove is closest from the top side than the recess.

According to an aspect, the head and the stem are generally cylindrical.The stem is of reduced diameter compared to the head. The die can easilybe supported by a die holder and a die exchanger can be used to replacea die by another.

According to an aspect, the identification tag is a radio frequencyidentification (RFID) tag. RFID tag are easy to use and to manage. Theirimplementation allows a good traceability of the die. The identificationtag may also be a Near-field communication (NFC) tag.

According to an aspect, the identification tag is covered by a material.This allows the outer surface of the die to not have any unwantedunevenness on the outside surface of the die.

Another object of the present invention is a joining tool systemcomprising:

a. a die for deforming material in a joining tool having a headcomprising a top side defining a die cavity in which material is to bedeformed, a bottom side opposite the top side and a lateral sidearranged between the top side and the bottom side, and a stem whichextends along a longitudinal direction from the bottom side of the head,wherein the die comprises an identification tag having an antenna forreceiving and transmitting signal and a storing element for storinginformation, and the antenna is wrapped around the head, such that thelatest entirely surrounds the head,

b. a die holder in which the die is supported such that the die isoperational with the die cavity being exposed for receipt of material,

c. a setting tool supported by one arm over the top side of the die,

d. a reader device which communicates and receives data on a contactlessbasis from the identification tag,

wherein the identification tag acts as a sensor.

The position of the identification tag allows it to act as a sensor andto reflect a change condition of the die. A damage of the die willdamage the antenna which prevents the communication with the readerdevice. One unique identification tag can be used for severalapplications: as a sensor, for labelling, for identification . . .

According to an aspect, the setting tool is supported by a first arm ofa C-frame and the die is supported by a second arm of the C-frame.

According to an aspect, the reader device is arranged on the C-frame.This allows an immediate and “in-situ” detection of a change of the diecondition with an ongoing communication. In another embodiment thereader device may be arrange at a particular distance from the C-frame.The manipulator can freely disposed the reader device at a preferredposition, depending on obstruction, needs . . .

Another object of the present invention is a method for identifyingand/or detecting the condition of a die for deforming material in ajoining tool, the die having a head comprising a top side defining a diecavity in which material is to be deformed, a bottom side opposite thetop side and a lateral side arranged between the top side and the bottomside, and a stem which extends along a longitudinal direction from thebottom side of the head, wherein the die comprises an identification taghaving an antenna for receiving and/or transmitting signal and a storingelement for storing information, and the antenna is wrapped around thehead, such that the antenna entirely surrounds the head, the methodcomprising the step of:

a. Providing a reader device which communicates and receives data on acontactless base from the identification tag,

b. Establishing a regular communication between the identification tagarranged on the die and the reader device,

c. Detecting a communication change between the identification tag andthe reader device in order to detect a change in the condition of thedie.

The method allows the use of the identification tag not only foridentifying the die but also as a sensor to detect a condition of thedie.

According to an aspect, the detected communication change between theidentification tag and the reader device is a communication breakdownwhich detects a breach at the surface forming the top side of the die.

According to an aspect, the storing element stores identification andservice life data, and the method further comprises the step of usingthe identification tag to detect an end of service life or a maintenancerequirement.

According to an aspect, the method further comprises the step of usingthe identification tag to detect an incorrect setting of the die.

According to an aspect, the position of the reader device to establish aregular communication with the identification tag is independent fromthe orientation or arrangement of the die.

Another object of the present invention is a non-transitory computerreadable storage medium having stored thereon computer readableinstructions that, when executed at a computer system, cause thecomputer system to perform at least some of the steps of the method foridentifying and/or detecting the condition of a die described above.Examples of a computer-readable storage medium include a random-accessmemory (RAM), read-only memory (ROM), an optical disc, flash memory,hard disk memory, and other memory devices that may use magnetic,optical, and other techniques to store instructions or other data andthat can be accessed by a machine.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention will readilyappear from the following description of embodiments, provided asnon-limitative examples, in reference to the accompanying drawings.

In the drawings:

FIG. 1 shows a schematic side view of a die with a stem, a head and anidentification tag in accordance with the present invention;

FIG. 2 shows a perspective view of a die with a stem, a head and anidentification tag in accordance with the present invention;

FIG. 3 shows a schematic perspective view of the head with anidentification tag of the die of FIG. 1 or FIG. 2;

FIG. 4 shows an alternative embodiment of a head with an identificationtag of a die in accordance with the present invention;

FIG. 5 shows a perspective view of the die with a material (or holtmelt) covering the identification tag;

FIG. 6 shows a schematic perspective view of a joining tool system witha die, a die holder, a setting tool and a reader device, in accordancewith the present invention;

FIG. 7 shows a flow chart of a method for identifying and/or detectingthe condition of a die, in accordance with the present invention.

On the different figures, the same reference signs designate identicalor similar elements.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring firstly to FIG. 1 and FIG. 2, there is shown a die 10 fordeforming material in a joining tool. The die 10 comprises a head 12 aswell as a stem 14. The die extends along a longitudinal axis X. Asillustrated, the head 12 and the stem 14 are circular in cross section.The stem 14 is of reduced diameter compared to the head 12. In otherembodiments, the head 12 and/or the stem 14 may have square or ovalcross sections.

The head 12 comprises a top side 16, a bottom side 18 and a lateral side20 arranged between the top side 16 and the bottom side 18. The lateralside 20 forms the outer circumference of the head 12. The top side 16forms an upper surface. The top side 16 defines a cavity (or die cavity)22 in which material is to be deformed. The head 12 is centered on thelongitudinal axis. As illustrated, the cavity 22 may be centered on thelateral side 20 along the longitudinal axis X. The stem 14 being ofreduced diameter compared to the head 12, an annular surface 24extending radially relative to the longitudinal axis X is defined on thebottom side of the head 12.

The head 12 may be provided with a rotary entrainment contour. Therotary entrainment contour may be formed by one or two radial slots onthe lateral side of the head 12.

The stem 14 extends along the longitudinal axis X from the bottom side18 of the head 12. The stem 14 is dependent from the head 12. In otherwords, head 12 and stem 14 form a one-piece part. The stem 14 isdestined to be inserted in a bore or a recess 46 in a die holder 26 (seeFIG. 6) being either an adapter or a part of a C-frame 44. The stem 14may comprise a locking contour allowing a locking position of the stem14 in the die holder 26.

The die 10 comprises an identification tag 28. The identification tag 28has an antenna 30 for receiving and/or transmitting a signal and astoring element 32 for storing information. The information stored inthe storing element 32 may be related to the die 10, like its type, itsservice life, its function and may be use to select the correct die 10to carry out a particular assembly (or joining application) or tocontrol that the mounted die 10 complies to the requirement needed tocarry out the assembly (or joining application).

The antenna 30 is wrapped around the head 12. In other words the antenna30 entirely surrounds the head 12. The position of the antenna 30 couldallow a 360 degrees reading position. In other words, the antenna 30 maytransmit data (or information) on its entire circumference.

The antenna 30 may be arranged, as illustrated in FIG. 1, FIG. 2, FIG. 3and FIG. 4 in a groove 34 or a slot extending around the head 12. Thegroove 34 extends around the head 12 on the lateral side 20. Forinstance the groove 34 extends in the vicinity of the top side 16, suchthat the antenna 30 is arranged close to the top side 16 of the die 10.The antenna 30 is used to transmit or receive information from or to thestoring element 32 on a contactless basis.

The dimensions of the groove 34 correspond to the dimensions of theantenna 30. Thus, the groove is particularly minimal or small, whichreduces the impact of the groove 34 on the service life of the die 10.

The storing element 32 may be arranged in a recess or cavity. The recess35 can be provided on the head 12 or on the stem 14. As seen in FIG. 1,FIG. 2, FIG. 3 and FIG. 4, the recess 35 is provided on the lateral side20 of the head 12. The groove 34 is closest from the top side 16 thanthe recess 35.

The storing element 32 is spatially separated from the antenna 30. Thisseparation reduces the risks of damages of the storing element 32. Evenif the antenna is damaged, the storing element may be still working anda process can be implemented afterward to read the data collected in thestoring element 32. In particular, the storing element 32 may bearranged in a location where the stresses and other mechanical strainsare lower than at the top side of the die.

The recess 35 is arranged in a location where it does not sensiblyimpact the service life of the die. More particularly, the recess 35 isarranged in a location at distance from the top side 16 or other workareas.

The storing element 32 and/or the antenna 30 are incorporated in the die10. The storing element 32 and/or the antenna 30 do(es) not protrudefrom the outer surface of the die 10.

As illustrated in FIG. 4, the identification tag 28 can be snap fittedwith the head 12. This snap fit connection allow the identification tag28 to be easily removed.

As illustrated in FIG. 1, FIG. 2 and FIG. 3 the identification tag 28,and more particularly the antenna 30 and the storing element 32 are eachfixed in the recess 35 and the groove and cannot be removed.

The storing element 32 can be fitted into the recess 35 or glued. Theantenna 30 can also be fitted into the groove 34 or glued. The storingelement 32 and/or the antenna 30 may be embedded in the die 10. Forinstance, the antenna 30 is arranged in the groove 34, the storingelement 32 is arranged in the recess 35. As illustrated in FIG. 5, boththe groove 34 and the recess 35 are covered with a material HM, suchthat the outside shape of the die 10 remain similar to the die of thestate of the art and no premature wear occurs. In particular, thematerial HM allows to remove any unwanted unevenness of the outsidesurface of the die 10. Besides, no further arrangement in the die holder26 are needed. The material HM covering the groove 34 and the recess 35(and therefore the antenna 30 and the storing element 32) can be anycovering material. More particularly, hot melt HM can be used. The hotmelt is a thermoplastic polyamide adhesive. This allows the fixation ofthe identification tag 28 in the die 10. The identification tag 28 isthus totally embedded in the die 10.

The identification tag 28 communicates on a contactless basis with areader device 36 through the antenna 30. The identification tag 28 maycommunicate through telemetry. For instance, the identification tag 28is, as illustrated, a radio frequency identification (RFID) tag 28. TheRFID tag 28 allows transmission of data between the die 10 and a readerdevice 36 on a contactless basis. The antenna 30 of the RFID tagamplifies and transmits radio signals from the die 10 to the readerdevice 36. The position of the antenna 30 all around the head 12 preventany fixed transmission/reception location of the reader device 36 or ofthe die 10. The antenna 30 may communicate with a reader device 36 atany time without any specific arrangement.

Referring now to FIG. 6 of the drawings, a joining tool system 38 isillustrated. The joining tool system 14 as illustrated is a rivetingtool system 38. However it is to be appreciated that whilst the specificembodiment described herein relates to the insertion of rivets it hasapplication to the formation of other joints including joints usingother fasteners that are inserted into a works piece using a die suchas, for example, clinching operation.

As shown on FIG. 6 a setting tool 40 is mounted on a first arm 42 of abody 44 above the die 10. The body 44 is a conventional C-frame. The die10 is inserted in a die holder 26. The die 10 is inserted in the dieholder 26 in an axial direction (as illustrated with the arrow A). Forinstance the die 10 is inserted along the longitudinal axis X. In otherembodiments, other insertion direction may be implemented. The stem 14is inserted into an aperture 46 of the die holder 26 and is fittedwithin the aperture 46. The fixation of the die 10 into the die holder26 is, for example, described in WO2015090965 and will not be furtherdescribed in this application. The die 10 can be interchangeable, asdescribed in WO2015090965 and the joining tool system 38 may be providedwith a die exchanger (not shown). The die exchanger is, for example,described in WO2015090965 and will not be further described in thisapplication.

The die holder 26 can be an adapter or directly integrated to theC-frame, as previously described. The die 10 is supported through thedie holder 26 in a second arm 48 of the body.

For instance, the setting tool 40 is mounted in an upper arm 42 of theC-frame whereas the die is supported by a lower arm 48 of the C-frame.Rivets (not shown) are inserted by the setting tool 40 into a workpiece(not shown). The workpiece can comprise one of more sheets of material.The workpiece is supported over the die 10. In order to carry out thejoining application, the setting tool 40 is driven such that amaintaining element (not shown) engage the workpiece and a punch isextended to insert the rivet. The body 44, as well known in the art, ismounted on a robot (not shown) and is movable toward and away from theworkpiece as required.

The joining tool system 38 may provided with the reader device 36. Thereader device 36 communicates and receives data on a contactless basisfrom the identification tag 28. The reader device 36 can communicate andreceive data on a contactless basis from the identification tag 28 on aregular basis, continuously or not.

The reader device 36 can be located at any convenient location which maybe proximate the die 10 and the die holder 26 or may be distaltherefrom. For example, the reader device 38 is provided, as illustratedin FIG. 6, on the body (or C-frame), close to the die holder 26. Moreparticularly the reader device 36 is arranged on the second arm 48 ofthe C-frame (or body 44). The reader device 36 can thus communicate withthe die 10 on a continuous basis.

In another embodiment (not shown), the reader device 36 may be distalfrom the area where the joining application is carried out. In suchcase, either the transmission is powerful enough to allow a remotelytransmission, or the die 10 is driven to the reader device 36, forexample between two joining application or at the end of a cycle, inorder to collect and/or send data.

The storing element 32 can store and communicate information (or data)concerning the identification of the die, the nature of the die, thefunction of the die, production data, cycle numbers, strength curve . .. Data can be written into the identification tag 28 by a writer device.

A processor may be provided for processing the data received and/or fordiagnosing a condition of the die 10. A processor, computer, or computersystem may be any kind of device, machine or dedicated circuit, orcollection or portion thereof, with processing capability such that itcan execute instructions. A processor may be any kind of general purposeor dedicated processor, such as a CPU, GPU, System 14-on-chip, statemachine, an application-specific integrated circuit (ASIC), aprogrammable logic array, a field-programmable gate array (FPGA), or thelike. A computer or computer system 14 may comprise one or moreprocessors.

The processor may be used to collect the information received by thereader device 36 to determine if the die 10 already set up or planned tobe used is the proper die to use for the current application, or if thedie 10 already set up or planned to be used is still in good condition,or if the die 10 already set up or planned to be used did not exceed itsservice life. The processor can also use the information received by thereader device 36 to determine the presence or not of a die 10 in the dieholder 26 and to prevent any erroneous operation.

The processor may execute a computer program product allowing the use ofthe collected data to diagnose a condition of the die. The diagnosis canbe based on the collected data only or can be based on the collecteddata and empirical or prepopulated data.

The position of the antenna 30 in the die 10 is such that a damage tothe top side 16 of the die, or more generally to the die 10 will alsodamage the antenna 30. If the antenna 30 is being damage, thecommunication between the reader device 36 and the storing element 32 isbroken. A breakdown from communication can thus be analysed by aprocessor as a default and a possible damage to the die 10. Theprocessor can order the actuator to stop its motion, such that thejoining process is interrupted.

The identification tag 28 has therefore (at least) three functions(identification of the die, storage of measured data, break detection).

The identification tag 28 acts as a sensor to detect the condition ofthe die and any damage caused to the die. A break of the die may bedetected immediately with a breakdown of the transmission between theantenna and the outside of the die.

The identification tag 28 acts as a labelling element, for example tocheck the origin of the die and detect a misuse of the die or aselection error.

The identification tag 28 can receive data relative, for example, to theuse of the die or any other production data.

FIG. 7 shows a flow chart of an embodiment of a method for identifyingand/or detecting the condition of a die.

Firstly a joining process is started (step S). By selecting apredetermined joining process, data like the type of die 10 needed, thematerial of the workpiece or the type of rivet for example may beprovided.

In a first step (step S1) the die 10 is inserted in the die holder 26.

Subsequently and/or simultaneously a communication (or transmission)between the die 10 and the outside of the die (for example the readerdevice 36 and/or the processor) is set up (step S2).

A test (step S3) is conducted to check the communication and/or to checkthat the transmitted data are correct with regard to the predeterminedjoining process to be carried out.

If the communication is broken or incorrect (NOK), the process can beinterrupted (step E). In an embodiment, if the communication is brokenor incorrect (NOK) the processor may indicate a default of the die 1(for example that the die 10 is damaged), and the die 10 can be forexample changed with a die exchanger.

If the data transmitted and/or received complies with the predeterminedjoining process (OK), the joining application is carried out (step S4).

Subsequently and/or simultaneously a communication (or transmission)between the die 10 and the outside of the die (for example the readerdevice and/or the processor) is set up (step S5).

A test (step S6) is conducted to check again the communication betweenthe die and the outside of the die (for example the reader device and/orthe processor).

If the communication is broken or incorrect (NOK), the process can beinterrupted (step E). In an embodiment, if the communication is brokenor incorrect (NOK) the processor may indicate a default of the die (forexample that the die 10 has been damaged), and the die 10 can be forexample changed with a die exchanger.

If the data transmitted and/or received complies with the predeterminedjoining process (OK), a further joining application is carried out (stepS4). In another embodiment, a joint application different from the firstapplication can be carry out. The die may be changed or not.

A writer device may be provided. The writer device may communicate withthe identification tag 28 and data concerning the joining applicationalready carried out may be transmitted to the identification tag 28 andstored in the storing element 32. The new data stored may be used laterby the processor to diagnose an end of service life, for example.

Generally, any of the functions, methods, techniques or componentsdescribed above can be implemented in software, firmware, hardware(e.g., fixed logic circuitry), or any combination thereof. The methodsdescribed herein could be performed by one or more processors executingcode that causes the processor(s) to perform the methods.

Although exemplary embodiments of the present invention have been shownand described, it will be appreciated by those skilled in the art thatchanges may be made to these embodiments without departing from theprinciples and spirit of the invention, the scope of which is defined inthe appended claims and their equivalents.

What is claimed is:
 1. A die for deforming a workpiece material in ajoining tool, the die comprising: a head comprising a top side partiallydefining a cavity in which the workpiece material is to be deformed, abottom side opposite the top side, and a lateral side arranged betweenthe top side and the bottom side; a stem which extends along alongitudinal axis from the bottom side of the head; and anidentification tag having an antenna for receiving and/or transmitting asignal, and a storing element for storing information, and the antennais wrapped circumferentially around the head, such that the antennaentirely surrounds the head.
 2. A die according to claim 1, wherein thedie further comprises a groove extending around the head on the lateralside between the top side and the bottom side, and the antenna isarranged in the groove.
 3. A die according to claim 1, wherein the diefurther comprises a recess, and the storing element is arranged in therecess.
 4. A die according to claim 3, wherein the recess is located onthe lateral side of the head.
 5. A die according to claim 1, wherein afirst distance between the antenna and the top side is smaller than asecond distance between the storing element and the top side.
 6. A dieaccording to claim 1, wherein the identification tag is a radiofrequency identification (RFID) tag.
 7. A die according to claim 1,wherein the identification tag is covered by a material.
 8. A joiningtool system for joining two workpiece materials, the joining tool systemcomprising: a die having a head comprising a top side partially defininga die cavity in which the workpiece materials are to be deformed, abottom side opposite the top side, a lateral side arranged between thetop side and the bottom side, and a stem which extends along alongitudinal direction from the bottom side of the head; anidentification tag having an antenna for receiving and transmittingsignal and a storing element for storing information, and the antenna iswrapped around the head such that the antenna entirely surrounds thehead, and the identification tag acts as part of a sensor; a die holderoperable for supporting the die such that the die cavity is exposed forreceipt of the workpiece materials; a setting tool supported by a firstarm over the top side of the die; and a reader device operable tocommunicate and receive data on a contactless basis from theidentification tag.
 9. A joining tool system according to claim 8, andfurther comprising a C-frame body, and the setting tool is supported bythe first arm of the C-frame and the die is supported by a second arm ofthe C-frame.
 10. A joining tool system according to claim 9, wherein thereader device is arranged on the C-frame.
 11. A joining tool systemaccording to claim 8, wherein the position of the reader device toestablish a regular communication with the identification tag isindependent from the orientation or arrangement of the die in the dieholder.
 12. A method for identifying and/or detecting the condition of adie for deforming material in a joining tool, the method comprising thesteps of: providing the joining tool comprising: a die having a headincluding a top side partially defining a die cavity in which thematerial is to be deformed, a bottom side opposite the top side, alateral side arranged between the top side and the bottom side, and astem which extends along a longitudinal direction from the bottom sideof the head; providing an identification tag including an antenna forreceiving and/or transmitting a signal, and a storing element forstoring information, and the antenna is wrapped around the head suchthat the antenna entirely surrounds the head; providing a reader devicewhich communicates and receives data on a contactless base from theidentification tag; establishing a regular communication between theidentification tag arranged on the die and the reader device; anddetecting a communication change between the identification tag and thereader device in order to detect a change in the condition of the die.13. A method according to claim 12, wherein the detected communicationchange between the identification tag and the reader device is acommunication breakdown which detects a breach at the surface formingthe top side of the die.
 14. A method according to claim 12, wherein thestoring element stores identification, production data and service lifedata, and wherein the method further comprises the step of using theidentification tag to detect an end of service life or a maintenancerequirement.
 15. A method according to claim 12, further comprising thestep of using the identification tag to detect an incorrect setting ofthe die.